Marfan syndrome is a multysistemic an autosomal-dominant disorder of connective tissue and cardiovascular complications determine its prognosis. We present a 32 year-old patient diagnosed five years previously after thoraco-abdominal aneurysm Standford B, and a current unplanned pregnancy. She was treated with beta blockers and evaluated with serial images of the aorta showing a stable thoraco-abdominal aneurysm initiated at the left subclavian artery to the right iliac artery of 41.8 mm at maximum diameter. The patient was hospitalized at 32 weeks to be evaluated in a multidisciplinary team planned delivery. Nuclear Magnetic Resonance on maternal spine detected dural ectasia at S2 and fetal evaluation shows growing at 20 percentile, hemodinamical wellbeing and normal echocardiography. After corticosteroids at 34 +3 weeks a cesarean section with tubal sterilization is performed, with continuous spinal anesthesia, without uterus compression and inmediate postoperative care at the Coronary Unit for 48 hours with satisfactory maternal evolution. The newborn presented a necrotizing enterocolitis at 7 days improving with medical therapy.